Hydrocarbon reservoirs are developed with drilling operations using a drill bit associated with a drill string rotated from the surface or using a downhole motor, or both using a downhole motor and also rotating the string from the surface. A bottom hole assembly (BHA) at the end of the drill string may include components such as drill collars, stabilizers, drilling motors and logging tools, and measuring tools. A BHA is also capable of telemetering various drilling and geological parameters to the surface facilities.
Resistance encountered by the drill string in a wellbore during drilling causes significant wear on the drill string, especially the drill bit and the BHA. Understanding how the geometry of the wellbore affects resistance on the drill string and the BHA and managing the dynamic conditions that lead potentially to failure of downhole equipment is important for enhancing efficiency and minimizing costs for drilling wells. Various conditions referred to as drilling dysfunctions that may lead to component failure include excessive torque, shocks, bit bounce, induced vibrations, bit whirl, stick-slip, among others. These conditions must be rapidly detected so that mitigation efforts are undertaken as quickly as possible, since some dysfunctions can quickly lead to tool failures.
Tri-axial accelerometers have been widely used in the drilling industry to measure three orthogonal accelerations related to shock and vibration during drilling operations. The magnitudes of the acceleration data provide a qualitative evaluation of the extent of the drill string vibration. The acceleration data combined with other information are typically used in the industry to produce a qualitative drilling risk index.
However, the analyses of the three orthogonal accelerations typically indicate the amount of the vibration during drilling operations. It does not provide any insight how the drill string moves around the borehole. Therefore, there is a need to transform the three orthogonal accelerations into actual motions of the drill string, providing a 2D/3D visualization how the drill string deviates from the ideal drilling condition. The drill-string motions, in turn, aid to rapidly identify drilling dysfunctions and to mitigate dysfunctions during drilling operations.